The authors' concluded that interventions delivered to individuals may increase cancer awareness and interventions delivered to communities may promote cancer awareness and early presentation, but the evidence was limited. The authors' conclusions reflected the evidence presented, but potential for language and publication biases and poor-quality designs of some included studies should be borne in mind.

Authors' objectives

To assess the effectiveness of interventions to raise cancer awareness and promote early presentation with cancer symptoms.

Searching

MEDLINE, EMBASE, PsycINFO and The Cochrane Library were searched for studies published in English from 2000 to November 2008. Search terms were reported. Reference lists of identified reports were scanned.

Study selection

Randomised controlled trials (RCTs) of interventions delivered to individuals and controlled or uncontrolled studies of interventions delivered to communities for the purpose of raising cancer awareness and promoting early presentation with cancer symptoms were eligible for inclusion. Eligible comparators for controlled studies were placebo, no intervention or usual care. Outcomes of interest were knowledge or beliefs related to cancer, time from symptom discovery to presentation or diagnosis, stage of disease at diagnosis, survival or mortality. Studies were excluded if they: evaluated individual level interventions that compared two different interventions or variants of an intervention; included only people at high genetic risk; only evaluated knowledge of checking behaviour techniques, health-checking behaviour, knowledge of screening, beliefs about cancer treatment, intentions to take up screening or screening uptake; reported composite outcomes, including those of interest, but which were not reported separately; or only reported post-intervention outcome measures on the same day of delivery of the intervention.

Interventions varied between studies and included: individual-level interventions that evaluated written information sent by post or given out in a waiting room with or without telephone counselling or an educational programme; and community-level interventions that included an interactive multimedia programme, annual media campaign, educational presentations and public education campaigns. Knowledge outcomes were evaluated from two weeks to 24 months after the intervention. Measurements of cancer knowledge varied between studies. Type of cancers included prostate, breast, oral and malignant melanoma. Studies were conducted in UK, Italy, Hungary, Honduras, USA, Sweden and the Netherlands.

Two reviewers independently selected studies for inclusion; disagreements were resolved by a third reviewer.

Assessment of study quality

Validity of RCTs of individual-level interventions were assessed with a checklist previously developed by review authors (Goldsmith et al. 2006) and evaluated appropriateness of study question, random assignment, allocation concealment, blinding of subjects or investigators, similarity of groups at baseline, differences between groups, validity of outcome measurements and appropriateness of statistical analysis. Validity of each study was rated as ++ (all or most criteria fulfilled), + (some criteria fulfilled) and - (few or no criteria fulfilled). Validity of community-level interventions was not formally assessed.

The authors did not state how many reviewers performed the validity assessment.

Data extraction

Two reviewers independently extracted data for relevant outcomes. Disagreements were resolved by a third reviewer.

Methods of synthesis

Studies were grouped by outcome in relation to cancer awareness or early presentation and combined in a narrative synthesis.

Results of the review

Fifteen studies (>10,519) were included in the review: five RCTs (n=3,877) that evaluated individual-level interventions and 10 studies (>6,642) that evaluated community-level interventions (four non-randomised controlled studies, one interrupted-time-series analysis and five before-and-after studies). The quality of the RCTs was rated moderate to good. The four non-randomised controlled studies used appropriate control groups. The interrupted-time series analysis was reported as being of high quality with appropriate analysis.

Individual level trials of cancer awareness (five RCTs): All five RCTs reported that the intervention increased cancer awareness in at least one respect. The effects were reported to be modest.

Community-level interventions of cancer awareness (four non-randomised controlled studies): There was limited evidence of effectiveness of community-level interventions to promote cancer awareness. Modest increases in knowledge were reported for an educational programme for breast cancer (approximately 6% after eight months) and a health promotion initiative for testicular cancer (20% after six weeks). No effect on knowledge was found for a public education campaign or an interactive multimedia kiosk.

Community-level interventions early presentation outcomes (six studies): There was limited evidence that public education campaigns reduced stage at presentation of breast cancer (two studies) and of malignant melanoma (two studies) and an increase in the proportion of participants who delayed presentation for less than three months (one study). Two studies that evaluated time from symptom discovery to diagnosis found no intervention effects; one study reported an association with a reduction in the proportion of people presenting with advanced disease.

Authors' conclusions

Interventions delivered to individuals may increase cancer awareness. Interventions delivered to communities may promote cancer awareness and early presentation, although evidence was limited.

CRD commentary

The review question was clear with appropriate inclusion criteria. Several relevant sources were searched, but no attempts were made to search for unpublished studies and only English-language studies were included; therefore, there was potential for language and publication biases. RCT validity was assessed with appropriate criteria; it appeared that other study designs were not evaluated. Appropriate methods were used to reduce reviewer error and bias in study selection and data extraction; it was unclear whether similar methods were used for validity assessment. There were differences between studies in terms of intervention, populations, outcomes and study designs. The authors appropriately reported potential for bias of uncontrolled studies. A narrative synthesis was appropriate given the differences between studies.

The authors' conclusions reflected the evidence presented, although potential for language and publication bias and the poor-quality designs of some of the included studies should be borne in mind.

Implications of the review for practice and research

Practice: The authors stated that there was some evidence that interventions delivered at an individual-level can promote cancer awareness over the short term, but there was no evidence that these interventions promoted early presentation with cancer symptoms.

Research: The authors stated that further research that evaluated individual-level interventions for promotion of cancer awareness should attempt to use robust study designs, measure outcomes over a longer term (months/years) and attempt to measure behavioural and stage outcomes in addition to knowledge and attitudes. There was also a need for standardised and validated measures of cancer awareness for different cancers and for duration of symptoms.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.